Uniscribe improvements

[Jeff L]

* * wrote:
> "If the device context is passed as NULL and Uniscribe needs to access
> it for any reason, Uniscribe returns the error code E_PENDING. This
> code is returned quickly, allowing the application to avoid
> time-consuming SelectObject calls."
>
> Whereas the current implementation will silently access an HDC even if
> the application passed NULL, which means the application doesn't get a
> chance to SelectObject the right font.
I have checked how this works by not selecting a font before the first 
ScriptShape.  The test run works as as specified and  Windows did not 
return E_PENDING in this case.  My reading of uniscribe is that its not 
too fussy about what fonts you use and accepts what ever the default is 
in the HDC.  The key thing is that once you have initialised a 
Script_Cache from a HDC then the font can't be changed cache.

Jeff